DE102015122224A1 - Flowmeter - Google Patents

Abstract

A flowmeter comprising a sensor signal generating sensor element (5) and a metallic, in particular produced in a generative manufacturing process, connecting element which connects the measuring signal generating sensor element with an opening or with a sensor nozzle (2) of a pipe (3), characterized in that the connecting element with a pressure-bearing component (7), comprising a sleeve (12) and a wall (18) extending over the entire cross-section in parallel projection in the course of a longitudinal axis (A) of the sleeve (12), wherein the pressure-bearing member (7 ) has at least one cable bushing (9) and a potting compound (8), wherein the potting compound (8), the sleeve (12) partially or completely fills, and wherein the pressure-bearing member (7) in the opening or in the sensor nozzle (2) of the tube (3), relative to the longitudinal axis of the tube (3), is arranged radially behind the connection element.

Description

The present invention relates to a flowmeter according to the preamble of claim 1.

The structural design of thermal flow meters is known per se. Starting from a mostly cylindrical hollow body having a base surface, at least two cylindrical pin sleeves extend in the direction of the interior of a tube. However, these pin sleeves are usually connected by welds with the cylindrical hollow body. A typical example is in the DE 10 2010 061 731 A1 shown and described.

Often joints are created by shocks. Depending on the type of joint, different welds can be used, which have different seam or joint shape and different types of welds. A distinction is made between butt and fillet welds. In butt seams, the lines of force run with a relatively uniform distribution of stress, while in fillet welds the lines of force are deflected, which leads to stress peaks.

In the field of thermal flow measurement, the usual procedure of joining and subsequent welding has disadvantages, since at the gap or impact the heat transfer changes with temperature change. This can lead to measurement errors.

Therefore, the production is recommended as a monolithic sensor housing. Such components with complicated shapes and with functional properties can be realized by so-called generative manufacturing processes. Such manufacturing processes rely on partial or complete fusion of granular material, e.g. Metal powder and metal grains. For this purpose, z. B. the so-called SLM method can be used. Alternatively, such a monolithic component can be produced by means of a so-called MIM (metal injection molding) method.

In the field of flow measurement, such components can be used as connection components between measuring signal-emitting sensor elements (heaters, temperature sensors, ultrasonic transducers and DSC sensors).

However, sensor housings must withstand certain pressure requirements. The sensor housings must withstand a static pressure of up to 40 bar. However, there are concerns that components that are not manufactured according to standardized methods can withstand such pressure requirements. This concerns in particular components that were manufactured according to the MIM or SLM process.

The present invention therefore sets in the task of providing a flow meter with a connection component, which connects the measuring signal generating sensor elements with a pipe, that is, an opening in the pipe or a sensor nozzle associated with the pipe, wherein the flow meter also meets the pressure requirements required in the flow measurement ,

The invention solves this problem by a flow meter with the features of claim 1.

A flow meter according to the invention comprises a measuring signal generating sensor element and a metallic connecting element, which connects the measuring signal generating sensor element with an opening or with a sensor nozzle of a pipe.

A flow meter according to the invention is preferably a thermal flow meter, an ultrasonic flow meter and / or a vortex flow meter.

A measuring signal generating sensor element is for a thermal flow meter, a heater and / or a temperature sensor for determining the temperature of a measuring medium. Both sensor elements may each comprise a heatable resistance thermometer, e.g. a Pt 100 or Pt 1000 element.

A measuring signal generating sensor element is in an ultrasonic flowmeter an ultrasonic transducer, which may be formed for example as a piezoelectric element.

A measuring signal generating sensor element may be a DSC sensor in the case of a vortex flowmeter.

The connection element allows the connection of the measuring signal generating sensor element with the pipe, in particular with an opening located in the pipe or with a sensor nozzle. The connection to the pipe can be made by the connection element directly or by the connection element in conjunction with other components, in particular by a pressure-bearing component.

The connection element can also advantageously fulfill additional functions. It may be formed, for example, in the form of a sensor housing for protecting the measuring signal generating sensor elements. In a thermal flow meter, it is advisable to design the sensor housing with two pin sleeves, which extend from a hollow body into the lumen of the tube. The sensor housing can have an at least partially comparatively thin housing wall for optimum heat transfer. Usually, pen sleeves are welded to the hollow body. In the context of the present invention, however, it is possible to use a monolithic sensor housing or a monolithic connecting element, in which the pin sleeves are connected to the hollow body free of connecting seams, in particular free of welding seams. This creates defined heat transfer.

In a further embodiment variant, the connection element can be designed in an ultrasonic flowmeter as a structure-sound-reducing or structure-sound-decoupling element which reduces or eliminates the structure-borne sound vibrations of the ultrasonic transducer towards the pipe. Structure-borne sound isolating structures may have very complicated geometric shapes, but are well manufacturable by additive manufacturing techniques. For a defined as possible power diversion, the design of the aforementioned element is recommended as a monolithic connection seam-free connection element.

In a further embodiment, the attachment element may have a stop for the paddle of a DCS sensor. a cage, which is connected to the pipe or the pipe wall. Here, too, generative production methods are applicable and a monolithic connection seam-free construction of this connection element is selected.

The connection element according to the invention is connected to a pressure-bearing component, which is part of the flowmeter. The pressure-bearing component comprises a sleeve. The sleeve may have a variable sleeve shell shape depending on the shape of the opening of the tube or the sensor nozzle of the tube. This can e.g. be a cylinder surface. However, it is also possible to provide a prism lateral surface. The cross section of the sleeve may e.g. be formed circular or rectangular.

On or in the sleeve, a wall is arranged, which is associated with the component. The wall may be formed as a flat plate or curved or dome-shaped. It extends over the entire cross section of the sleeve. The cross section need not necessarily lie on a plane perpendicular to the longitudinal axis of the tube, but the cross section is to be understood as a parallel projection along a plane perpendicular to the longitudinal axis. Thus, curved or obliquely arranged in the sleeve walls are covered by the subject of the present invention.

The pressure-bearing component has at least one cable feedthrough. This cable guide may preferably be formed as an opening through the wall.

In addition, the pressure-bearing member has a potting compound, wherein the potting compound, the sleeve 12 partially or completely. The potting compound prevents the escape of measuring medium from the opening and / or the sensor nozzle in the event of material failure of the connecting element under high pressure. Accordingly, the pressure-bearing component secures at higher pressures, for example at pressures of up to 40 bar, before the outlet of the measuring medium. For this purpose, the pressure-bearing member in the opening of the tube and / or in the sensor nozzle, based on the longitudinal axis of the tube, arranged radially behind the connection element.

Preferably, the metallic attachment element may be used in an additive manufacturing process, e.g. made of a granular material. The type of manufacturing process can be determined in the case of metallic materials on the basis of the micrograph.

Alternatively, the metallic attachment element may be made in an MIM process. Again, the manufacturing process can be determined on the basis of the micrograph.

Thus, even with material failure of the connection element, an outlet of the measuring medium can be reliably prevented.

Advantageous embodiments of the invention are the subject of the dependent claims.

It is advantageous if the flowmeter is designed as a thermal flow meter. The monolithic metallic connecting element can be advantageously designed as a sensor housing of a thermal flow meter, with a hollow body and two pin sleeves which protrude from the hollow body.

Alternatively, the flowmeter can be advantageously designed as an ultrasonic flowmeter and the monolithic metallic connection element can be designed as a structure-borne sound-reducing element, in particular as a structure-borne sound-decoupling element.

Also alternatively, the flowmeter may be configured as a vortex flowmeter. The monolithic metallic attachment element may also advantageously comprise a stop for limiting the movement of a sensor paddle of a DSC sensor.

The pressure-bearing component may have at least one electronic component which is embedded in the potting compound. As a result, this component is additionally improved in its shape and pressure stability.

Particularly preferably, the monolithic metallic attachment element may be made by a generative manufacturing process of a granular metallic material or alternatively be prepared by means of an MIM primary molding process. Such materials allow the design of geometrically complicated metallic components. However, at present, the risk of pressure-related material failure compared to comparable components manufactured using traditional manufacturing processes is considered higher. In order to meet the required pressure requirements also in the flow measurement, the use of the pressure-bearing component according to the invention is recommended.

To additionally secure the potting compound from being forced out of the sleeve, the pressure-bearing component can advantageously have undercuts on the inner surface of the sleeve for anchoring the potting compound.

A particularly pressure-stable construction of the pressure-bearing component can advantageously be achieved if the wall thickness of the wall to the diameter of the sleeve cross section of the sleeve has a ratio of preferably at least 1 to 30, particularly preferably of at least 1 to 10.

The grommet may be formed at least as a hole in the wall, which hole has a mean hole diameter of 0.2 to 1.5 mm.

The pressure-resistant component may advantageously be welded and / or screwed into the opening of the tube and / or in the sensor neck.

Hereinafter, further advantageous embodiments of a connection element will be described, which are particularly preferably used in the embodiment of a flowmeter according to the invention as a thermal flow meter.

The connection element in its configuration as a metallic sensor housing has a hollow body for connection to a plug-in device and / or a pipe wall. A plug-in device may e.g. be a linkage, at the end of which the aforementioned sensor housing is arranged. This linkage is then inserted through an opening, which is usually located in the gravity field at the top of a pipe, into the pipe and fixed in an opening. The wall of the sensor housing which delimits the environment is thus partially or completely exposed to a flow of the measuring medium located in the pipe. As an alternative to the insertion device, the metallic sensor housing can also be fixed directly or by means of a pipe extension fixed to a pipe wall. However, the manner of fixing the sensor housing or the hollow body is only of secondary importance in the context of the present invention.

The aforementioned hollow body has a base. This base can be formed, for example, flat or curved.

The sensor housing has at least two pin sleeves, which protrude from the base into the inner region of a tube. The pen sleeves may e.g. be formed cylindrical or prismatic.

The metallic sensor housing is integrally formed and the pin sleeves and the hollow body are connected seamlessly. So far, it was customary to add the pen sleeves with the hollow body and then to weld. In these designs, a heat transfer was created, which changes with temperature change of the medium and production-related is not reproducible for each sensor housing. This can lead to a measurement error that is individually large for each sensor housing.

Seamless means in the context of the present invention that neither a weld nor an adhesive or solder seam is present as a connection between the pin sleeves and the hollow body.

It is advantageous if the metallic sensor housing is designed as a monolithic component. This means that the sensor housing is made of a complete material. Although generative manufacturing processes also involve combinations of several metals or metal alloys, e.g. Steel and titanium, realizable, these are included in the present invention, but not preferred over the monolithic design.

It is advantageous if each of the pin sleeves each having a terminal portion having a medium-contacting end face and that in a first of the two pin sleeves, in particular in the terminal portion of this pin sleeve, a heater is arranged and that in a second of the two pin sleeves, in particular the terminal portion of this pin sleeve, a temperature sensor for determining the temperature of the medium is arranged. This embodiment describes a typical thermal flow meter with a heater and a temperature sensor, which largely thermally decoupled from each other, are stored in two separate metallic pin sleeves. These are often referred to as sensor elements. Often used as a heater and a temperature sensor two similar heatable resistance thermometers, such as PT100 sensors, of which a resistance thermometer is actively heated and thus used as a heater. These sensor elements enable flow measurement. Such a configured flow meter is known per se and has been commercially sold for many years, but the mostly cylindrical pin sleeves are always welded to the corresponding heatable resistance thermometers in the previous versions of the prior art with the hollow body. In a preferred variant according to the invention, several heatable resistance thermometers can also be introduced into a sleeve.

It is advantageous if the pinholes of the thermal flow meter at least in the terminal portion has a wall thickness of less than 0.5 mm, preferably between 0.1-0.4 mm. Due to the very thin wall thickness, the sensor reacts quickly when the flow rate changes.

A thermal flowmeter always has some sensitivity to the ambient temperature. The best possible heat distribution, e.g. the heat radiated by the heater, along the metal wall of the pin sleeve is preferred. In this context, it is advantageous if the wall thickness, at least in the region of the terminal section, varies by less than 20%, preferably by less than 10%.

A good response with simultaneous good thermal decoupling between heater and temperature sensor can be achieved if the two aforementioned pen sleeves are designed to be particularly thin and long. It is advantageous if the terminal section of the pin sleeve has a cylindrical lateral surface with a diameter d1 and that the terminal section extends over a length l2, characterized in that the ratio l2 / d1 is greater than or equal to 5, preferably greater than or equal to 7, is. Such pen sleeves, which are also integrally and seamlessly integrated in a sensor housing, are not yet known.

For pressure stability and chemical stability, it is advantageous if the sensor housing consists of steel and / or titanium and / or Hastelloy.

The sensor housing may preferably have at least three pin sleeves, that is to say the first, the second and preferably a third pin sleeve, which preferably run parallel to one another. As described above, two of the pin sleeves can be equipped with a heater and a temperature sensor for determining the temperature of the medium. They allow the flow measurement in a conventional manner. The third sensor sleeve may also have a heater, preferably in analogous configuration to the heater, the other two pen sleeves. For example, in the case of uneven soiling or corrosion of the respective pin sleeves, the determination and / or compensation of a sensor pressure is advantageously made possible. This additional pin sleeve can also advantageously be integrally and seamlessly connected to the hollow body.

It is advantageous if the sensor housing has a flow obstacle, which is arranged to one of the three aforementioned pen sleeves, that one of the pen sleeves, starting from the flow of the sensor housing, from a predetermined flow direction partially or completely in the flow shadow of the flow obstacle, while the other two pen sleeves are arranged outside the flow shadow. Preferably, a heater is arranged in the third pin sleeve. This allows a direction detection depending on whether the flow of the measured medium from the aforementioned flow direction and thereby the flow and the removal of the heat of the heater is hindered by the flow obstacle, or if the flow direction of the measuring medium is opposite to the above-mentioned flow direction. In the latter case, the third pin sleeve is not in the flow shadow of the flow obstacle.

The flow obstruction may preferably be described as a prism-shaped pin sleeve, e.g. be triangular cross-section, which is particularly preferably parallel to the other three pen sleeves.

The third pin sleeve and / or the pin-shaped element can protrude from the base of the hollow body in the inner region of the tube and be connected seamlessly with the hollow body, wherein the total length of the third pin sleeve and / or the flow obstacle is preferably less than the total length of the first two stick tubes. As a result, the heater in the third sensor element does not affect the flow measurement, since it is arranged on another plane perpendicular to the longitudinal axis of the sensor housing than the heater and the temperature sensor of the first two pen sleeves.

The sensor housing preferably has an arcuate bracket, which spans at least the first and second pin sleeves and which is preferably connected to the hollow body. This bracket is the flow guide. The Arrangement of the at least two pin sleeves can form a connection axis, which lies in a plane of symmetry. The bracket is preferably also on this plane of symmetry and is formed symmetrically along this plane of symmetry.

In a preferred embodiment, the bracket is seamlessly connected to the hollow body.

The length of the terminal section is advantageously at least 2 mm, preferably 3-10 mm, the total length of a pin sleeve is preferably at least 10 mm. Correspondingly long pen sleeves enable a particularly good thermal decoupling.

The sensor housing of the flowmeter according to the invention can be produced by means of a generative manufacturing process, preferably by means of a jet melting process. Although corresponding sensor housings are also via other manufacturing methods, such. can be realized by primary molding, in particular by the metal injection molding, however, it has been found that particularly good manufacturing tolerances and particularly thin-walled components can be achieved with the aforementioned preferred manufacturing methods.

The invention will be explained in more detail with reference to an embodiment of a thermal flow meter and with the aid of the accompanying drawings. This description and the figures are to be understood as exemplary and in no way limiting the scope of the present invention. Show it:

1 Sectional view of a sensor housing of a thermal flow sensor according to the invention.

Conventional thermal flow measuring devices usually use two heat resistivity thermometers configured as identically as possible, which are arranged in, usually pin-shaped metal sleeves, so-called stingers, or in cylindrical metal sleeves and which are in thermal contact with the medium flowing through a measuring tube or through the pipeline. For industrial application, both resistance thermometers are usually installed in a measuring tube; The resistance thermometers can also be mounted directly in the pipeline. One of the two resistance thermometers is a so-called active sensor element, which is heated by means of a heating unit. As a heating unit, either an additional resistance heating is provided, or the resistance thermometer itself is a resistance element, for. B. to an RTD (Resistance Temperature Device) sensor, the by converting an electrical power, for. B. is heated by a corresponding variation of the measuring current. In the area of thermal flow measurement, the active sensor element is also often called a heater. The second resistance thermometer is a so-called passive sensor element: it measures the temperature of the medium.

Usually, in a thermal flow meter, a heatable resistance thermometer is heated so that sets a fixed temperature difference between the two resistance thermometer. Alternatively, it has also become known to feed a constant heat output via a control / control unit.

If no flow occurs in the measuring tube, then a temporally constant amount of heat is required to maintain the predetermined temperature difference. If, on the other hand, the medium to be measured is in motion, the cooling of the heated resistance thermometer depends essentially on the mass flow rate of the flowing medium. Since the medium is colder than the heated resistance thermometer, heat is removed from the heated resistance thermometer by the passing medium. Thus, in order to maintain the fixed temperature difference between the two resistance thermometers in a flowing medium, an increased heating power for the heated resistance thermometer is required. The increased heating power is a measure of the mass flow or the mass flow of the medium through the pipeline. The heating power can be described by a so-called power coefficient PC.

If, however, a constant heating power is fed in, the temperature difference between the two resistance thermometers decreases as a result of the flow of the medium. The respective temperature difference is then a measure of the mass flow of the medium through the pipe or through the measuring tube.

Thus, there is a functional relationship between the heating energy necessary for heating the resistance thermometer and the mass flow through a pipeline or through a measuring tube. The dependence of the heat transfer coefficient on the mass flow of the medium through the measuring tube or through the pipeline is used in thermal flowmeters for determining the mass flow. Devices based on this principle are offered and distributed by the applicant under the name 't-switch', 't-trend' or 't-mass'.

In 1 is a variant of a thermal flow meter according to the invention 1 shown in more detail. One recognizes in particular one Housing of a sensor of the thermal flowmeter 1 , which subsequently as a sensor housing 4 referred to as. This sensor housing 4 is made of metal and can be designed as Einstecksensor and for example in a sensor neck 2 a pipe 3 or in a hole of a pipe 3 be arranged. This pipe 3 may be a measuring tube or may be associated with an existing pipeline.

In addition to the sensor has the thermal flow meter 1 also an evaluation unit 10 which may usually be part of a transducer.

The sensor housing described below 4 a sensor only represents a particularly preferred embodiment of the invention.

The sensor housing 4 has a hollow body 13 on, which directly in the sensor neck 2 can be arranged.

The hollow body 13 has a curved base, starting from which at least two, a first and a second, pen sleeves 6 into the lumen, so the inside of the tube 3 protrude.

The hollow body 13 is in the embodiment of the 1 dome-shaped shown. However, it can also have a different shape and, for example, cylindrical, frusto-conical or truncated pyramid-shaped.

In 1 are a total of two pen sleeves 6 shown. However, it is also possible for further pin sleeves, for example three or four pin sleeves, to be provided, wherein the flow meter can preferably combine further functionalities, eg drift detection and direction detection, in a thermal flow meter.

The present invention, in a simplified embodiment, only the two pen sleeves 6 exhibit. The pen cases 6 are with the hollow body 13 integral and free of connection seams, in particular connected in the connection area. As a seam within the meaning of the present invention is a weld, glued seam, solder seam and the like to understand. Particularly preferably, the housing, that is, the entirety of pin sleeves and hollow body, formed monolithic.

The first and second pin sleeve 6 each have a medium-contacting end face 14 on. This is in 1 arched, but can also be trained.

Each of the two pen sleeves have, in particular in the region of the medium-contacting end face 14 , a sensor element 5 on which inside the respective pin sleeve 6 is arranged. A first sensor element 5 is designed as a heating element and a second sensor element 5 is designed as a temperature sensor, to determine the medium temperature. Both sensor elements can be designed as a heatable temperature sensor, for example a Pt-100 or Pt-1000 resistance temperature sensor.

The pen cases 6 can each be stepped, whereby a better insertion and positioning of the sensor elements 5 in the pen sleeve 6 through the terminal opening on the side facing away from the media of the pen sleeve 6 can be done.

The pin sleeve 6 is the sensor housing 4 assigned, which is to be understood in the context of the present invention as a connection element, which the sensor elements 5 with the sensor socket 2 combines.

The geometric design of a respective pin sleeve 6 is such that starting from the end face 14 first a first section 20 with a cylindrical pin sleeve wall and a first continuous cylinder jacket diameter d1. After a grading 15 follows a second section 19 with a cylindrical pin sleeve wall and a second continuous cylinder jacket diameter d2. The second section may for example also have a conical shape. In this variant, the diameter d2 corresponds to an averaged value.

On the second section 19 then follows a third section 16 with a conical shape. The transition area between the first and second sections 19 and 20 is not abrupt, but has a continuous increase in diameter from the first diameter d1 to a second diameter d2. It is a corresponding grading 15 therefore not a sudden, but a gradual change in diameter. Then the pin sleeve goes into the third section 16 about, which is frusto-conical and in which the diameter d gradually in the course of the truncated cone to a transition region to the hollow body 13 gradually grows. The pen cases 6 have a length l1 of at least 10 mm.

Due to the stepped construction of the pen sleeves advantageously a higher stiffness of the pen sleeves can be achieved.

The section 20 is the end face according to the definition of the present invention 14 assigned. In this section 20 a first of the two pen sleeves 6 is each a sensor element 5 arranged. The sensor element, in particular the heating element, does not necessarily have to be on the end face 14 or cylindrical surface of the pin sleeve, but may preferably be thermally coupled via a copper bridge with the wall of the pin sleeve. The same applies to the other optional pen sleeves. A corresponding arrangement and its advantages are in the DE 10 2008 015 359 A1 described in detail.

In the section 20 the second of the two pen sleeves 6 a temperature sensor is arranged to determine the temperature of the medium. This can also be designed as a heatable resistance thermometer, wherein during operation of the thermal flow meter 1 preferably in each case one of the resistance thermometer actively heated and one of the resistance thermometer can be operated unheated.

The wall thickness of the pen sleeves 6 is at least in the section 20 less than 0.5 mm, preferably less than or equal to 0.4 mm, in particular 0.1 to 0.4 mm. Due to the thin wall thickness, a particularly favorable heat transfer can be achieved.

The length l2 of this section 20 may be at least 2 mm, but preferably 3-10 mm.

The ratio of length l2 to diameter d1 is for the first section 20 preferably greater than 5, more preferably equal to or greater than 7.

In a preferred embodiment of the invention, the average ratio d _{average value} / l1 for the entire pin sleeve, preferably greater than 4, wherein the diameter always refers to the respective length of the portion of the pin sleeve, in which the diameter is actually present. In the case of a truncated cone, as in section 16 , averaging the diameter can be done.

The sensor housing 4 is made of metal. As a particularly preferred metal, steel, in particular stainless steel, or Hastelloy can be used. Alternatively, for example, for strongly corrosive media, titanium can also be used as wall material.

The sensor housing is preferred 4 made monolithic. As a result, a defined heat transfer is achieved.

In addition, the sensor housing 4 then be provided with a metallic outer coating, if necessary, to increase the resistance to certain media. However, this outer coating does not count according to the present invention to the housing 2 but as an addition to the case 4 applied material layer.

The sensor housing 4 is particularly preferably manufacturable in a generative manufacturing process. Particularly preferred are beam melting, such as selective laser melting, which is also known as SLM method to produce such an article with a correspondingly thin wall thickness and appropriate length of the pen sleeves.

In the SLM process, a metal powder can be applied in a thin layer on a surface. The metal powder is then completely locally melted by laser radiation and solidified to a solid material layer in a layer thickness of typically 15-150 microns. Then the surface is lowered by the amount of the layer thickness and applied a new layer of material. In this way, gradually forms the housing 4 out of the sensor. Material stresses and corrosion-susceptible seams are not present.

The thermal flow meter according to the invention 1 also has a pressure-bearing component 7 which is located at an interface 21 to the hollow body 13 followed. The pressure-bearing component preferably has a deformation stability, at least up to a maximum pressure of 40 bar.

The pressure-bearing component 7 has a sleeve 12 with a longitudinal axis A on and a wall 18 which extends over the entire cross section of the sleeve 12 extends. The sleeve may preferably have a circular or rectangular cross-section. It may particularly preferably have a cylindrical shape.

The surface normal of the wall 18 may preferably parallel to the longitudinal axis A of the sleeve 12 extend. The wall 18 However, it can also be slanted in the sleeve 12 be arranged.

The face and the wall 18 do not necessarily have to be terminal on the sleeve 12 They may also be arranged, for example, in the middle of the sleeve shape of the annular wall region and extend over the entire cross section.

In the sleeve 12 are preferably electronic components, such as boards and the like, arranged. These electronic components are in one potting compound 8th embedded. The potting compound 8th in particular, fill the sleeve 12 partially or completely off. In the wall 18 is at least one hole or there are several holes as cable glands 9 arranged. These serve to carry out one or more signal lines and / or power supply lines 17 between the sensor elements 5 and the evaluation device 11 , The holes may preferably have a mean hole cross section between 0.2 and 1.5 mm.

For securing the position of the potting compound 8th has the sleeve 12 on the inside an undercut 11 on. Alternatively, or in addition to the undercuts, the sleeve 12 for anchoring the potting compound 8th Grooves and / or have a thread. At the same time a better seal the potting compound is achieved.

The wall thickness of the wall 18 points relative to a diameter of the sleeve cross-section of the sleeve 12 of preferably at least 1 to 30. Especially with a dome-shaped form of the wall 18 a smaller wall thickness can be chosen than with a flat shape of the wall 18 ,

The wall thickness of the wall 18 has a flat shape based on a diameter of the sleeve cross-section of the sleeve 12 of preferably at least 1 to 20, more preferably at least 1 in 10.

So can the wall 18 have a wall thickness of preferably at least 0.5 mm and more preferably from 1 to 2 mm.

The one or more openings or holes of the cable gland 9 may preferably also with potting compound 8th be filled.

The potting compound may be formed, for example, based on an epoxide.

The sleeve 12 and the wall 18 are preferably formed of a metal and more preferably of stainless steel or Hastelloy. It is preferably constructed monolithically.

In 1 are the two measuring signal generating sensor elements 5 , So the heating element and the temperature sensor, via a monolithic connecting seam-free connection element in the form of a sensor housing 4 to the pipe 3 or to the sensor nozzle 2 of the pipe 3 arranged.

Corresponding connection elements are also known in the field of ultrasonic flowmeters and in the field of vortex flowmeters.

Ultrasonic flowmeters can be an element for reducing structure-borne noise, which carries the ultrasound-generating element, for example the ultrasound transducer, and by means of which it is fixed to a tube wall. Also at this point, following this element to reduce structure-borne noise, a pressure-bearing component, analogous to the component 7 of the 1 be arranged. This structure-borne sound-reducing element is monolithic and can be produced in particular by one of the generative production methods already described above.

In vortex measuring devices capacitive sensors, so-called DSC sensors, are often used. To a mechanical deformation of a sensor paddle. In case of pressure surges, it is recommended to provide a stop. This stop can be arranged for example in cage or bow shape in the region of the sensor paddle and limit its movement in addition. This element can also be produced by means of a generative manufacturing process. This stop is monolithic and in particular produced by one of the already described above generative manufacturing process.

LIST OF REFERENCE NUMBERS

1

 thermal flow meter

2

 sensor nozzle

3

 pipe

4

 sensor housing

5

 Sensor elements (heater and T-sensor)

6

 first and second pin sleeve

7

 pressure-bearing component

8th

 potting compound

9

 Grommet

10

 evaluation

11

 undercut

12

 shell

13

 hollow body

14

 face

15

 gradation

16

 section

17

 Signal & power supply lines

18

 wall

19

 section

20

 section

21

 interface

p

 print

A

 Longitudinal axis of the sleeve

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102010061731 A1 [0002]
• DE 102008015359 A1 [0078]

Claims (11)

Flowmeter comprising a sensor signal generating sensor element ( 5 ) and a metallic, in particular produced in a generative manufacturing method, connecting element which the measuring signal generating sensor element with an opening or with a sensor neck ( 2 ) of a pipe ( 3 ), characterized in that the connecting element with a pressure-bearing component ( 7 ), comprising a sleeve ( 12 ) and a wall ( 18 ), which extend over the entire cross-section in parallel projection in the course of a longitudinal axis (A) of the sleeve ( 12 ), wherein the pressure-bearing component ( 7 ) at least one cable feedthrough ( 9 ) and a potting compound ( 8th ), wherein the casting compound ( 8th ) the sleeve ( 12 ) partially or completely, and wherein the pressure-bearing component ( 7 ) in the opening or in the sensor neck ( 2 ) of the pipe ( 3 ), relative to the longitudinal axis of the tube ( 3 ), is arranged radially behind the connection element. Flowmeter according to claim 1, characterized in that the flowmeter is a thermal flowmeter ( 1 ) and that the metallic attachment element is a sensor housing ( 4 ) of a thermal flow meter ( 1 ), comprising a hollow body ( 13 ) and two pen sleeves ( 6 ) which from the hollow body ( 13 ) protrude. Flowmeter according to claim 1, characterized in that the flowmeter is an ultrasonic flowmeter and that the metallic connection element is a structure-borne sound reducing element. Flowmeter according to claim 1, characterized in that the flowmeter is a vortex flowmeter and that the metallic connection element comprises a stop for limiting the movement of a sensor paddle of a DSC sensor. Flowmeter according to one of the preceding claims, characterized in that the pressure-bearing component ( 7 ) has at least one electronic component, which in the potting compound ( 8th ) is embedded. Flowmeter according to one of the preceding claims, characterized in that the metallic connecting element is produced by a generative manufacturing process, in particular by an SLM process, from a granular metallic material or produced by an MIM process. Flowmeter according to one of the preceding claims, characterized in that the metallic connecting element is monolithic. Flowmeter according to one of the preceding claims, characterized in that the pressure-bearing component ( 7 ) one or more undercuts ( 11 ) on the inner surface of the sleeve ( 12 ) for anchoring the potting compound ( 8th ) having. Flowmeter according to one of the preceding claims, characterized in that the wall thickness of the wall ( 18 ) based on a diameter of the sleeve cross-section of the sleeve ( 12 ) has a ratio of preferably at least 1 to 30, more preferably at least 1 in 10. Flowmeter according to one of the preceding claims, characterized in that the cable bushing ( 9 ) at least as a hole in the wall ( 18 ) is formed, which hole has a mean hole diameter of 0.2 to 1.5 mm. Flowmeter according to one of the preceding claims, characterized in that the pressure-bearing component ( 7 ) in the opening of the pipe or in the sensor neck ( 2 ) of the pipe ( 3 ) is welded and / or screwed.

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